Towing A Caravan With 1.9 Diesel (130hp)

[lazyb5]

Sorry Sher

i was on about my caravan tyres not the car tyres. On the car I`ve got 2 dunlop 2020 on the front and 2 Falken on the rear seem ok. My previous fronts were Michelin forget the type about 85 quid each lasted a year about 11k so will try the falken when front dunlops go.

Never thought about how much we put in the car good point though (now trying to find where i got 85% of Kerbweight from) thinking about a new van so will be able to look at the twin axle with a little bit more interest.

Yep the 40k cambelt is pants only another 18k before i spend another 350 quid whats wrong with a chain anyway

Edited August 12, 2007 by lazyb5

[TerryM]

A question for anyone! If one ignores fuel consumption is the V6 a better option for towing caravans in respect of torque and gear box reliability?

 

Thanks

[insider]

I personally don't tow anything but would probably recommend a diesel. Even the 90PS TDI delivered more torque than the old 2.8 (12v) engine - 240Nm at 1,900 rpm instead of 235Nm at 4,200rpm. The 115PS and 130PS diesels produce 310Nm at 1,900rpm which is still greater than the newer 2.8 (24v) engine - 268Nm at 3,200rpm. So, if you're looking for lots of torque lower down the rev range then a diesel is probably your best bet, but I'm sure any of the 2.8s would be more than capable of towing.

[TerryM]

Thanks for the reply Insider. My worries are more to do with the strength and reliability of the auto box. I've read so many comments that the 115bhp autobox is a bit fragile when it comes to towing that I wonder if the box on the VR6 engine is more capable. Any ideas?

 

Regards

TerryM

[Sher]

I'm sure that the V6 will tow well but always at higher revs and will sound more strained/fussy. There is more to towing than just torque and economy.

 

The shape of the Galaxy/Sharan means that the caravan sits more in the slipstream of the towing vehicle and there is less pressure on the front of the caravan when towing. This force on the front of the caravan is what makes caravans likely to snake at higher speeds with or without a stabilizer.

I have a twin axle Chateau Caravan from 1990 (Max Gross Weight 1600kg) which has a smaller front profile than my larger Hobby (single axle) . The Chateau with no stabilizer and 4 wheels is absolutely rock steady at all speeds when towed by the Galaxy and hardly seems to be there. I have taken it upto 70mph and it showed absolutely no sign of instability. The same caravan behind the more streamlined Rover saloon was a pig at over 60mph. Behind a Mondeo 1.8Td (89bhp) hatchback was more stable at these speeds, was underpowered, but did not feel half as powerful as the Rover. The difference seemed to be much smaller.

The Hobby with its larger profile and excellent stabilizer is also rock steady but when tall vehicles pass at high speed one knows about it. If the gap is too narrow the suction caused as this happens is not a nice experience.

 

I used to tow with a V6 2.7litre Rover 800 but that was always sounding fussy, 17-18mpg Towing. I would expect similar for a Galaxy V6 (Comments from those who do tow with a V6?)

Its impossible to ignore consumption. The need to refill every 225 miles max along Continental Motorways at enormous prices over Supermarkets saw to that (Just the same as the UK)

 

I have a Dutch friend with a small petrol engined 4 wheel drive Mitsubishi (the road Tax in Holland for diesel Cars is about 600

[fosterman]

Have just returned from 2 weeks in France (St Jean de Monts) in the Vendee region.

 

Covered approx 1200 miles at average of around 42 mpg.

 

Had 6 up (so to speak) 3 adults & 3 children.

 

Whilst not towing a caravan, was towing a fairly large trailer, though is fair to say did not extend beyond the extremities of the vehicle.

 

Also, to be on safe side, was carrying some 8 litres of water due to regular overheating problems which nobody seems to be able to replicate, and therefore unable to solve ( have followed threads on this subject and made suggestions to various mechanics - usually results in sharp intakes of breath, have decided to live with it for now and carry spare water with me !!!! Not best solution, but refuse to spend more money trying to resolve issue.)

 

On a brighter note, found towing was very easy and am very pleased with economy and comfort.

[seatkid]

Also, to be on safe side, was carrying some 8 litres of water due to regular overheating problems which nobody seems to be able to replicate, and therefore unable to solve ( have followed threads on this subject and made suggestions to various mechanics - usually results in sharp intakes of breath, have decided to live with it for now and carry spare water with me !!!! Not best solution, but refuse to spend more money trying to resolve issue.)

 

I recently read a post on HJ site (regarding 1.9 vs 2.0 VAG engines) claiming to be from a VAG tech. Claimed latest engines (2.0) suffer a lot from heads cracking into inlet ports and going porous. Said that first signs were mysterious loss of water and rough starting. Claimed all VAG diesels 1.9 and 2.0 - particularly high powered variants were "on the limit" regarding head design.

 

I wonder if this is what we have been seeing here with some members overheating problems while towing or after remaps?

[Smilge]

The shape of the Galaxy/Sharan means that the caravan sits more in the slipstream of the towing vehicle and there is less pressure on the front of the caravan when towing. This force on the front of the caravan is what makes caravans likely to snake at higher speeds with or without a stabilizer.

 

Sorry mate .... don't agree with that. Snaking is due to incorrect load distribution caused by most of the load being behind the van axle and air pressure on the front of the van is basically an air brake which will increase your fuel consumption. That's it.

[Sher]

Reply to Bleano as regards

 

Snaking is due to incorrect load distribution caused by most of the load being behind the van axle

 

I do not disagree with the fact that incorrect load distribution means that once started the pendulum like motion produced is more difficult to prevent.

In certain circumstances it can manifest itself at lower speeds.

 

My previous statement was an incomplete explanation of the effect. The following is nothing more than a starting point.

 

Even an old fashioned tow ball with grease presents some resistance to twisting and turning. All anti snaking devices all seem to rely on a damping effect be it by friction etc.

 

However, the primary cause of the instability is the air stream/pressure on and around the front of the caravan, in particular, that sitting in the turbulent air.

 

This pressure/turbulence is not a constant and is the primary cause of the instability which will happen with any van having the best load distribution and fitted with antifriction devices, if the conditions are right.

 

It was the wind blowing at certain speeds ( not that fast) and the turbulence produced around the Square/rectangular box sections of the Tacoma Narrows Bridge ( I think everyone has seen at some time or other) which caused what looked like a solid road suface, with cars upon it ,to undulate in a frightening manner and eventually cause the collapse.

If you have not seen it here it is:-

 

http://www.youtube.com/watch?v=P0Fi1VcbpAI

 

All bridges are now designed with this in mind ( along with many other factors as well)

 

I'm sure that tall sided vans passing at high speed exagerate the turbulence around the caravan in such a way that they can cause snaking to begin. This is an effect I have mentioned before. They push the rear of the van sideways and a short time later the front. If this is at the correct rate they will amplify the swing and start the oscillation. With enough damping the oscillation will reduce. Otherwise it just gets worse as the turbulent air flow pushes on one side and then the other. Slowing down helps (if one has time when this happens) since it alters the rate at which the turbulent air flows around the van.

Snaking is a resonance effect. Vibrate a wine glass at the correct frequency and it will shatter as the vibrations build up.

[mumof4]

Now ive never towed anything in all the time ive been driving, but i have driven the Galaxy in high winds in Scotland where there was no shelter from the wind and the effect on the gal was in my mind frightening....the car was being buffeted from all directions , Now..the way i understand it,when towing something higher bodied than the car you are driving, isnt that going to create drag?as surely the wind will go around the car and smack the caravan at its highest points?..(think thats what Bleeno meant anyway)

Soo....the way i see it..the faster you are travelling the more drag created by the van also there is wind pressure yes?..and say you go from a road that is sheltered in someway say by trees either side to an open road.....is there then more drag and pressure against the van say coming from all angles which may create a snaking effect?i say this because not all roads are straight and wind does not always travel in one direction does it?..soooo....say you go from a straight road to go round a corner at speed, wont that effect everything?

Ive seen snaking happen numerous times on different roads, seen the consequences also..

can snaking be put down to any one thing or can it be a combination of things like load distribution / driver experience /speed and the wind??

 

Its early and if im talking bollox then ignore me. <_<

[Smilge]

Agree with you on the resonance effect Sher and yes Mum there are numerous factors that will induce "snaking" very similar to "fishtailing" on aircraft. The centre of gravity and pressure are a main factor and affected by numerous variables. The centre of gravity is 3 dimensional and the closer that gets to the towing point the less likely the rig will snake. The problem with that is the you then exceed the noseweight and wreck the suspension on the car. So ideally the weight distribution should be over the caravan axle. Any mass has momentum once accelerated (MxV) and placing a load behind the axle will amplify the effect. The only time I have had a rig snake was when going to fast, so I do agree that the differential air pressure between the front and rear of the van can induce snaking through turbulence. A good discussion.

[tim-spam]

I recently read a post on HJ site (regarding 1.9 vs 2.0 VAG engines) claiming to be from a VAG tech. Claimed latest engines (2.0) suffer a lot from heads cracking into inlet ports and going porous. Said that first signs were mysterious loss of water and rough starting. Claimed all VAG diesels 1.9 and 2.0 - particularly high powered variants were "on the limit" regarding head design.

I would think that this is just another of many myths and misinformation pedalled on that particular website. Are there any statistics to back this myth up? The TDI 115, 130 and 150 engines have been around for quite a while now, and all seem to be pretty robust to high mileages. The only 'common' problems seem to be MAF's and VNT's sticking, and these two problems certainly are not unique to these engines.

[Sher]

Sorry to seem a dope but what is a VNT?

 

I know a MAF is a Mass Air flow meter but all searches for VNT or VNT's give only 1 result.

 

The one above!

[tim-spam]

Variable Nozzle Turbocharger.

 

Basically, this type of turbocharger has variable geometry, which allows the boost pressure to be continuously varied between upper and lower limits determined by the ECU. In practice, this allows the engine to produce high torque right down to around 1300-1400rpm, with the VNT mechanism progressively backing off above this to keep the boost pressure and turbocharger speed within reasonable limits.

Edited September 4, 2007 by tim-spam

[Sher]

As opposed to Variable Vane Turbocharger.

 

The VNT method will be easier to apply.

 

Though how one would apply VVT to a centrifugal blower? I suppose it may be possible. Or do modern Turbos include an element of axial-flow design?

 

Thanks for the reply

[tim-spam]

VNT, VVT and variable geometry turbochargers are all basically similar. The rotor geometry is obviously fixed - it would be a little difficult to make this variable when spinning at more than 200,000rpm. On the exhaust side, there is a ring of vanes around the rotor, which control the direction and amount of exhaust gas driving the rotor - see www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html for a fuller picture. Edited September 4, 2007 by tim-spam